Separable assembly for electrical units



July 6, 1943. B. N. FOSTER SEPARABLE ASSEMBLY FOR ELECTRICAL UNITS Filed April 7, 1942 Patented July 6, 1943 SEPARAELE ASSEMBLY FOR ELECTRICAL UNITS Benjamin Norton Foster, Keene, N. H., assignor Kingsbnry Machine Tool Corporation,

Keene, N. EL, a corporation of New Hampshire Application April '7, 1942, Serial No. 438,028

'2 Claims.

The present invention relates to a separable assembly for employment with electrical units which are served through flexible conductors.

One of the features of the invention is the provision of a construction in which the terminal assembly permits relative movement of its lead-in parts.

Another feature of the invention is the provision of a terminal assembly which can be cheaply and simply constructed and engaged.

Another feature of the invention is the construction and arrangement of the parts so that they establish protection against penetration of fluids while assuring mechanical and electrical engagement of parts.

With these and other features as objects in view as will appear in the course of the following specification and claims, an illustrative form of practicing the invention is shown in the accompanying drawing in which the figure represents a cross section through a solenoid having a pair of the terminals associated therewith, one of the terminals being shown in elevation and the other in section.

In the illustrative form shown in the drawing, a solenoid comprises an external case l8 having a coil assembly H therein. This coil assembly is supported on the sleeve I2 and is held in position by the cap E3. The plunger is, having longitudinal grooves or kerfs around its periphery as shown in my prior Patent 1,987,555, slides within the sleeve l2, and is normally forced outwardly by a spring l5. A pole-piece It is provided at the inner end of the case Iii for receiving the plunger 14 at its inward limit of movement. A spring guide ii is positioned within the case I and within the spring [5. The plunger M has a transverse notch IS in its end for receiving a connecting link by which the solenoid can actuate any desired element, with employment of a securing and pivot pin in the aperture l9.

Such solenoids are employed in the art under conditions where they must be protected against penetration of fluids to the coil, and often under conditions by which the assembly must be easily and quickly inserted in or removed from a surrounding housing.

In the form illustrated in the drawing, this solenoid is shown as positioned within a housing body 20, and fits snugly in this body so that any heat generated in the solenoid can be dissipated rapidly through the metal of the housing.

The terminal wires 25, 23 of the coil ll must be connected to a source of supply, and for this purpose the present structure is employed. The coil 1 i may be wound upon the sleeve l2, between the end members 21, 28, which preferably are of insulating material. The end member 23 is provided with two projections or towers 29 which are hollow for receiving the corresponding connecting wires 25, 26. Each of these towers projects through an aperture 30 in the end of the case Iii, with a tolerance allowance for the reception thereof. The projecting ends of the towers 29 have peripheral grooves 3| preferably formed with a curvature blending with the outer surface of the end of the case Hi. The periphery of each tower from its groove to the end constitutes a curved tapering flank 32 A metal eyelet 33 has its reduced hollow shank seated in the bore 34 of the tower, and has its radial flange 35 seated against the end of the tower. In assembly, the conductor 25, for example, has a portion of its insulation removed prior to being inserted into the bore 34, So that a bare end thereof extends through the eyelet 33. This end is then twisted or knotted and is secured by solder to form a head-piece 36 which is solid and bonded to the eyelet 33.

A flexible jacket 4!] of elastic material, such as rubber, is employed to enclose and protect the electrically conductive parts for each terminal. For this purpose, the jacket has an inwardly extending rib portion 4| for engagement in the groove 3!, being normally smaller in diameter than the corresponding mating parts, so that it is under tension when in position. The jacket has a radially projecting flange 32 which is received within a rabbet 43 of the housing cap 23a, the thickness of the jacket being in its normal position slightly greater than the depth of this rabbet 43, so that it is compressed when the parts are assembled and thereby serves as a gasket to prevent penetration of fluid through the wall of the housing cap 2% at the corresponding points.

The housing cap 20a has an aperture 44 for receiving the jacket when the same has bee assembled upon the tower.

The jacket 49 is hollow and receives a cable 59 which has an insulating jacket and a conductor which preferably is of stranded type. The jacket has a normal internal diameter less than the external diameter of the cable '53, so that a fluid-tight seal is produced by telescoping these parts together.

A metal eyelet 5| has its hollow shank positioned within the jacket 41] and also has a radial flange 52 for engaging an internal shoulder 53 in the jacket 40. In the assembly of the parts, a portion of the insulating material of the cable 50 is cut away to expose the conductor, and this is introduced through the eyelet 5| and then knotted or twisted, and secured to the eyelet by soldering to form a bonded head-piece 56. It will be noted that this can be effected easily prior to the introduction of the eyelet 5| into the jacket 40.

A distending coil spring 55 is positioned within the jacket 45 and bears against the radial flanges 35 and 52 of the two eyelets.

After the coil II has been wound upon the sleeve I2 between the end members 21, 28, and the terminal wires 25, 26 have been fastened to the eyelets 33 on the towers 29, the assembly can be accomplished by introducing the coil into the case Ill and securing it by the cap l3. The end of a cable 50 is inserted through the jacket 40, and the insulation is removed for a length slightly greater than the length of the eyelet 5|. The eyelet 5| is slipped over the bared conductor and the conductor is secured to the eyelet to form the headpiece 5B. The cable 50 is now pulled until the radial flange 52 of the eyelet 5| engages with the internal shoulder 53 of the jacket 48. The distending spring 55 is now slipped into the jacket 40 until it bears against the radial flange 52. The entire assembly of cable, jacket, eyelet and spring is engaged with the tower 29, with the jacket 40 stretching over the curved flank 52 of the tower until the rib 4| of the jacket engages in the groove 3|. This is repeated for the other cable 50 in this illustrated form with two terminal connections. illustrated solenoid and terminal unit can be assembled then in the housing cap 20a by extending the cables 50 and the jackets 4|) through the proper apertures 44 of the housing cap. The housing body 20 is slipped over the solenoid unit, and screws 201) are used to draw the housing body solidly against the casing l0, leaving a slight gap between the cap 26a and the housing body 20; and compressing the flange 42 between the end of the case l and the bottom of the rebate 43 so that it can act as a gasket for forming a sealed joint against the entrance of fluids.

The clearance of the jacket ill in the aperture 44 is less than the depth of interengagement of the rib 4| in the groove 3| so that tension upon the cable 59 does not cause separation when the parts are in assembled condition, and the elasticity of the parts prevents such separation accidentally during insertion and removal of the unit.

The flange 42, when gripped, further assures 4 against separation of the parts when assembled.

Disassembly and removal of a solenoid unit for inspection, repair or replacement can be easily efiected in the reverse manner by withdrawing the screws 20b for securing the housing body 20 in position, removing the body 20, and sliding the solenoid unit out of the housing cap 20a. The jackets 40 may now be pulled from the towers 29, and the solenoid unit is free. It will be noted that the flexible material of the jacket 4!] permits also a pre-assembly of the jacket with the cable 50, and the introduction of this assembly through the aperture 44 of the housing,

The solenoid may be employed for many purposes in the industrial arts. The housing body 2|] may be held in a machine structure, and a connecting link engaged by a pivoting pin in the aperture 9 can establish connection to a lever to be moved. The spring normally holds the plunger I4 toward theright in the drawing.

This

When current is supplied to the winding, the plunger is retracted into the position shown in the drawing, thus pulling the link and moving the lever to a new position. When the circuit is broken, the spring l5 projects the plunger toward the right again, and the lever is restored.

It is obvious that the invention may be practiced in other ways without departing from the scope of the claims.

I claim:

1. A separable terminal assembly for connecting a cable with an electrical unit mounted in a housing, comprising a tower extending through an aperture in the housing and having a peripheral groove within the housing wall, a flexible jacket surrounding and gripping the outer end of the tower and having a rib engaged in the groove, said jacket having a clearance in the aperture less than the depth of the rib and groove whereby to prevent separation when the parts are in assembled condition, said jacket having an aperture for receiving an end of the cable, a conductor element on the tower electrically connected to a conductor of the unit and providing a first abutment, a second conductor element mounted in the jacket and electrically connected to a cable wire and providing a second abutment opposite the first abutment, and a metal compression spring positioned between'said abutments for holding the jacket distended and electrically connecting the abutments.

2. A separable terminal assembly comprising a hollow insulating tower having a peripheral groove and a tapering flank from said groove to its end, a metal eyelet supported on the end of said tower and connected to a conductor extending inside said tower; a flexible jacket contacting said flank and engaged in said groove for maintenance against axial separating movement, said jacket having a first cavity for receiving the end of an insulated cable, and also having an enlarged cavity communicating with the first cavity; a second metal eyelet supported in the jacket and connected to a conductor of said cable, said eyelets being positioned in opposed relation in said enlarged cavity, and a resilient conductive member in said enlarged cavity and engaged with said eyelets for electrically connecting them and holding them spaced apart.

3. A separable terminal assembly for an electrical unit having a separable outer housing with an aperture, comprising a hollow insulating tower supported on said unit and extending into said aperture, a metal eyelet supported on the end of said tower and connected to a conductor extending inside said tower, a flexible jacket surrounding the end of said tower havin a peripherally projecting elastic flange positioned and gripped by compression between the unit and the housing, said jacket having a first cavity for receiving the end of an insulated cable, and also having an enlarged cavity communicating with the first cavity; a second metal eyelet supported in the jacket and connected to a conductor of said cable, said eyelets being positioned in the assembly in opposed relation in said enlarged cavity, and a resilient conductive member in said en- 'larged cavity and engaged with said eyelets for electrically connecting them and holding them spaced apart.

4. A separable terminal assembly for an electrical unit secured in a housing having an aperture and having a rabbet'at the inner end of the aperture, comprising a hollow insulating tower supported on said unit and extending into said aperture, said tower having a peripheral groove, a metal eyelet supported on the end of said tower and connected to a conductor extending inside said tower, a flexible jacket surrounding the end of said tower and having a rib engaged in said groove and having a peripherally projecting elastic flange positioned in said rebate and gripped therein by compression between the unit and the housing, said jacket having a first cavity for receiving the end of an insulated cable, and also having an enlarged cavity communicating with the first cavity; a second metal eyelet supported in the jacket and connected to a conductor of said cable, said eyelets being positioned in opposed relation in said enlarged cavity, and a resilient conductive member in said enlarged cavity and engaged with said eyelets for electrically connecting them and holding them spaced apart.

5. A separable assembly for a solenoid, comprising an outer housing having a body and a cap, an inner assembly including a winding, an end member of insulating material for supporting the winding and having a tower formed integral therewith and projecting therefrom in an axial direction, a case surrounding the winding and end member and having an aperture in its end wall for receiving the tower, the housing having an opening aligned with said aperture, an elastic jacket engaged over the tower and having a flange positioned between the said end wall and the inner surface of the housing, conductor means located in said jacket and connected to the winding, and releasable clamping means for holding the cap and body together around the case and for compressing said flange in its position for establishing a sealed joint at said aperture.

6. A separable terminal assembly comprising a support, a hollow insulating tower extending through an opening in the support, a conductor extending through the tower and having an enlarged portion at the end of the tower, a flexible jacket surrounding the tower and having a hollow portion extending free of the same, a conductor with an insulated covering extending from the jacket and having an enlarged portion within the jacket, distending conductive means in the jacket engaged with said enlarged portions, said jacket also having an external peripheral flange, and means for clamping said flange against the support.

7. A separable terminal assembly comprising a support, a hollow insulating tower extending through an opening in the support, a conductor extending through the tower and having an enlarged portion at the end of the tower, an elastic flexible jacket surrounding the tower and having a hollow portion extending free of the same, a conductor with an insulated covering extending from the jacket and having an enlarged portion within the jacket, distending conductive means in the jacket engaged with said enlarged portions, said tower having an external peripheral groove, said jacket having an internal rib engaged in said groove, and separable means closely surrounding the jacket and connected to the support for preventing disengagement of the rib from the groove when the parts are assembled.

BENJAMIN NORTON FOSTER. 

